The present invention relates to a recorder of the type recording an image on a medium by depositing toner on the medium and, more particularly, to a method of producing a record head for an electrostatic ink jet recorder.
Non-impact recording schemes are attracting increasing attention because they produce only a negligible degree of noise during operation. Among them, an ink jet recording scheme is capable of recording an image directly on a medium at a high speed despite its simple configuration, and practicable even with plain papers. Various kinds of ink jet recording systems heretofore proposed include one using ink consisting of a carrier liquid and toner particles dispersed in the liquid. In this system, a voltage is selectively applied between needle-like ejection electrodes and a counter electrode facing the ejection electrodes and located behind a sheet or recording medium. The resulting electric field causes a coloring material contained in the ink to electrostatically fly toward the sheet, forming an image on the sheet. A record head for such a system includes a substrate on which ejection electrodes are formed independently of each other. Meniscus forming members each overlies one of the ejection electrodes. A cover covers the meniscus forming members and has an ink inlet port and an ink outlet port. Fine ejection openings or slits are formed by the substrate, meniscus forming members, and cover. Ink introduced into the head via the ink inlet port forms meniscuses at the front ends or tips of the meniscus forming members.
The above conventional record head, however, has the following problems left unsolved. Because the meniscus forming members are implemented by a photoconductive resist, their thickness is limited to several tens of microns. Further, because the meniscus forming members are formed by photolithographic exposure and development, their front corner portions or ejection points are not sharp. These in combination prevent meniscuses formed thereon from having a stable shape.
Technologies relating to the present invention are taught in, e.g., WO 93/11866 and Japanese Patent Laid-Open Publication No. 4-241955.